What are the effects of treatments for bulimia nervosa in adults?

LIKELY TO BE BENEFICIAL

Cognitive Behavior Therapy (CBT) for Bulimia Nervosa

One randomized controlled trial (RCT) identified by a systematic review found that CBT for bulimia nervosa improved the clinical effects of bulimia compared with a control group on a waiting list or no treatment. One RCT found no significant difference in remission rate or symptoms between CBT plus exposure response prevention and CBT for bulimia. Two RCTs found no significant difference in remission of binge vomiting between guided self-help CBT and CBT for bulimia after about one year. One systematic review identified two RCTs that found that significantly more persons abstained from binge eating and purging after CBT for bulimia compared with interpersonal psychotherapy at the end of treatment, but not at one year of follow-up. One RCT found no significant difference between hypnobehavior therapy and CBT for bulimia behavioral symptoms, but the two groups were not balanced at baseline. One RCT found no clinically important difference in binge frequency between motivational enhancement therapy and CBT for bulimia.

Two RCTs found no significant difference in remission or symptoms between CBT for bulimia and f luoxetine. Two RCTs comparing tricyclic antidepressants versus CBT for bulimia found mixed results. One found that CBT for bulimia improved remission compared with imipramine, and the other found no significant difference in remission rate between CBT for bulimia and desipramine. Two RCTs found no significant difference in remission rate or symptoms between CBT for bulimia alone or plus tricyclic antidepressants. Two RCTs found no significant difference in remission rate or symptoms between CBT for bulimia alone or plus fluoxetine.

Three RCTs identified by a systematic review found that f luoxetine 60 mg daily increased the number of persons with clinical improvement but not remission compared with placebo. One small RCT found that citalopram 40 mg daily reduced the frequency of binge eating and purging behavior compared with placebo. Two RCTs found no significant difference in remission or symptoms between CBT for bulimia and fluoxetine. We found no RCTs of other selective serotonin reuptake inhibitors (fluvoxamine, paroxetine, or ser-traline). One RCT found no significant difference in remission between fluoxetine and pure self-help CBT or between fluoxetine and combination treatment.

Monoamine Oxidase Inhibitors

RCTs identified by a systematic review found that monoamine oxidase inhibitors improved remission rate compared with placebo, but they found no significant difference in improvement in bulimic symptoms or depression scores.

Tricyclic Antidepressants

One systematic review found that tricyclic antidepressants (desipramine and imipramine) improved bulimic symptoms and reduced binge eating compared with placebo. Two RCTs comparing tricyclic antidepressants versus CBT for bulimia found mixed results. One RCT found that imipramine was not as effective at improving remission as CBT was for bulimia, and the other found no significant difference in remission rate between desipramine and CBT for bulimia. Neither RCT found a significant difference between treatment with a tricyclic antidepressant alone and the combination treatment.

Topiramate

One small RCT found that topiramate reduced the number of binge/ purge episodes and improved quality of life compared with placebo after 10 weeks.

Two RCTs found no significant difference in remission rate or symptoms between CBT for bulimia plus tricyclic antidepressants and either treatment alone. One RCT identified by a systematic review found no significant difference in remission rate or symptoms between CBT for bulimia plus fluoxetine and either treatment alone. One RCT found no significant difference in remission rate between pure self-help CBT plus fluoxetine and unguided self-help CBT alone or fluoxetine alone.

UKNOWN EFFECTIVENESS

CBT Plus Exposure Response Prevention Enhancement

One RCT found no significant difference in vomiting frequency between CBT plus exposure response prevention and being on a waiting list, although it found that exposure response prevention improved depression scores compared with being on a waiting list. One RCT identified by a systematic review found no significant difference in remission rate or symptoms between CBT plus exposure response prevention and CBT for bulimia.

Pure or Unguided Self-help CBT

Two RCTs found no significant difference in remission or reduction in binge/purge frequency between pure or unguided self-help CBT and being on a waiting list, although they might have lacked power to detect a clinically important difference. One RCT found no significant difference in remission between unguided self-help CBT and fluoxetine alone or unguided self-help CBT plus fluoxetine.

Guided Self-help CBT

One RCT found no significant difference in behavioral symptoms between face-to-face or telephone-guided self-help CBT and being on a waiting list. Two RCTs found no significant difference in remission of binge vomiting between guided self-help CBT and CBT for bulimia after about one year.

Cognitive Orientation Therapy

We found no RCTs on cognitive orientation therapy in persons with bulimia nervosa.

Interpersonal Psychotherapy

We found no RCTs comparing interpersonal psychotherapy versus no treatment, placebo, or a waiting list control group. One systematic review identified two RCTs, which found that significantly fewer persons abstained from binge eating and purging with interpersonal psychotherapy compared with CBT for bulimia at the end of treatment. However, there was no difference between treatments at one-year follow-up.

Hypnobehavior Therapy

One RCT found limited evidence that hypnobehavior therapy improved abstinence from binge eating and purging in the short term compared with being on a waiting list. The same RCT found no significant difference between hypnobehavior therapy and CBT for bulimia symptoms, but the two groups were not balanced at baseline.

Dialectical Behavior Therapy

We found limited evidence from one small RCT that dialectical behavior therapy increased cessation of binge eating or purging and improved bulimic symptoms compared with being on a waiting list. It found no significant difference in depression scores between dialectical behavior therapy and being on a waiting list.

Motivational Enhancement Therapy

We found no RCTs comparing motivational enhancement therapy versus no treatment, placebo, or being on a waiting list. One RCT found no clinically important difference in binge frequency between motivational enhancement therapy and CBT for bulimia for four weeks.

Mirtazapine

We found no RCTs.

Reboxetine

We found no RCTs.

Venlafaxine

We found no RCTs.

What are the effects of discontinuing treatment in persons in remission?

UNKLIKELY TO BE BENEFICIAL

Discontinuing Fluoxetine

One RCT found that continuing fluoxetine 60 mg daily is more effective than placebo for maintaining a reduction in vomiting frequency in persons who have responded well to an initial eight-week course of fluoxetine.

Definition

Bulimia nervosa is an intense preoccupation with body weight and shape, with regular episodes of uncontrolled overeating (i.e., binge eating) associated with use of extreme methods to counteract the feared effects of overeating. If a person also meets the diagnostic criteria for anorexia nervosa, the diagnosis of anorexia nervosa takes precedence.1 Bulimia nervosa can be difficult to identify because of extreme secrecy about binge eating and purging behavior. Weight may be normal, but there is often a history of anorexia nervosa or restrictive dieting. Some persons alternate between anorexia nervosa and bulimia nervosa. Some RCTs included persons with sub-threshold bulimia nervosa or a related eating disorder called a binge eating disorder. Where possible, only results relevant to bulimia nervosa are reported in this chapter.

Incidence and Prevalence

In community-based studies, the prevalence of bulimia nervosa is between 0.5 and 1.0 percent in young women, with an even social class distribution.2–6 About 90 percent of persons diagnosed with bulimia nervosa are women. The numbers presenting with bulimia nervosa in industrialized countries increased during the decade that followed its recognition in the late 1970s, and “a cohort effect” was reported in community surveys,2,7,8 implying an increase in incidence. Since that time, it is likely that the incidence has plateaued or even fallen, with an incidence of 6.6 per 100,000 reported in the United Kingdom in 2000.9 The prevalence of eating disorders such as bulimia nervosa is lower in nonindustrialized populations,10 and it varies across ethnic groups. Black women have a lower rate of restrictive dieting than do white American women, but they have a similar rate of recurrent binge eating.11

Etiology

The etiology of bulimia nervosa is complex, but sociocultural pressures to be thin and the promotion of dieting do appear to increase risk.12 One community-based case control study compared 102 persons with bulimia nervosa versus 204 healthy control participants and found higher rates of the following in persons with the eating disorder: obesity, mood disorder, sexual and physical abuse, parental obesity, substance misuse, low self-esteem, perfectionism, disturbed family dynamics, parental weight/shape concern, and early menarche.13 Compared with a control group of 102 women who had other psychiatric disorders, women with bulimia nervosa had higher rates of parental problems and obesity.

Prognosis

A 10-year follow-up study (50 persons with bulimia nervosa from a placebo-controlled trial of mianserin treatment) found that 52 percent receiving placebo had fully recovered, and only 9 percent continued to experience full symptoms of bulimia nervosa.14 A larger study (222 persons from a trial of anti-depressants and structured, intensive group psychotherapy) found that, after a mean follow-up of 11.5 years, 11 percent still met criteria for bulimia nervosa, whereas 70 percent were in full or partial remission.15 Short-term studies found similar results: about 50 percent of persons made a full recovery, 30 percent made a partial recovery, and 20 percent continued to be symptomatic.16 There are few consistent predictors of longer-term outcome.

Good prognosis has been associated with shorter illness duration, a younger age of onset, higher social class, and a family history of alcohol abuse.14 Poor prognosis has been associated with a history of substance misuse,17 premorbid and paternal obesity,18 and, in some studies, personality disorder.19–22 One study (102 women) of the natural course of bulimia nervosa found that 31 percent and 15 percent still had the disorder at 15 months and 5 years, respectively.23 Only 28 percent received treatment during the follow-up period.

In an evaluation of the response to CBT, early progress (more than a 70 percent reduction in purging by session 6) best predicted outcome.24 A subsequent systematic review of the outcome literature found no consistent evidence to support early intervention and a better prognosis.25 A more recent systematic review evaluating the cost-effectiveness of treatments, and prognostic indicators found only four consistent pretreatment predictors of poorer outcome for treatment of bulimia nervosa: features of borderline personality disorder, concurrent substance misuse, low motivation for change, and a history of obesity.26

This is one in a series of chapters excerpted from Clinical Evidence, published by the BMJ Publishing Group, London, U.K. The medical information contained herein is the most accurate available at the date of publication. More updated and comprehensive information on this topic may be available in future print editions of Clinical Evidence, as well as online at
http://www.clinicalevidence.com (subscription required). Those who receive a complimentary print copy of Clinical Evidence from United Health Foundation can gain complimentary online access by registering on the Web site using the ISBN number of their book.